Manufacture of methyl alcohol



July 19, 1932. DREF S 1,868,096

MANUFACTURE OF METHYL ALCOHOL Filed May 27. 1950 Teeevez.

HEN RY DREYFUS INVENTOR wmM h ATTORNE Y5 Patented July 19,1932

HENRY DBEYI US, LOI ID ON', ENGLAND mmrracruan or mm ancon or.

Application filed Kay 27, 1980, Serial No. 455,989, and. in Great Britain June 5, 19 29.

This invention relates to the synthesis of methanol by the subjection of mixtures of carbon monoxide and hydrogen to the action of catalysts under elevated temperatures and pressure. Numerous substances, particularly catalysts com rising copper, manganese ortheir com oun s, are very active in promoting .the synt esis of methanol, but their use on an in- 10 dustrial scale has been diflicult or impossible v owing totheir sensitivi? tosulphur poisoning. For this reason t 0 industrial manufacture of methanol is usually performed in presence of zinc oxide or zinc .oxide and chromium oxide.

The present invention provides a process whereby the catalysts sensitive to sulphur poisoning, and particularly catalysts comprising copper or manganese (or compounds of co per or manganese) can be successfully applied to the industrial manufacture' of methanol.

According to the invention methanol is prepared by passing the reaction gases under the requisite conditions of temperature and pressure for the formation of methanol first over one or more catalyst masses-composed of zinc :oxide or zinc oxide and chromium 8 oxide and thereafter over one or more'meth- -anol catalysts sensitive to sulphur poisoning, .and particularly catalysts comprising copper, manganese 'orcompounds of copper or manganese.

In performing the reaction the reaction gases are passed successively through a numberof reaction vessels arranged in series as an open systeni (i. e. not as a closed circuit). By these means a substantially complete con- 40 version ofthe reaction gases or vapors may be readily efl'ected.

- The process of the invention may be performed under pressures and temperatures usually or hitherto employed for the particx ular synthesis envisaged and the catalyst or catalysts employed, and such temperatures and pressures may be similar or dissimilar as between reaction vessels in the system.

In their passage from one reaction vessel the next, the reaction vapours are treated to remove' products of the conversion, as for instance by condensation.

a The following example serves to illustrate one convenient method of preparing metha- 1101 in accordance with the. invention 86 Ewample I Y b A stream of water gas (or other ind strial gas) containing between about and v I GO and 30 and 45% hydrogen is passed un- 60 der a pressure of between 50 and 150 atmospheres through a chain-of react1on v arranged in series. In the first reaction vessel or vessels of the seriesis placed a catal composed of pure zinc oxide. In the reea maining= reactlon vessels of the senes 1s placed a methanol catalyst contaming copper or manganese, e. g..a mixture of copper oxide and zinc oxide. The temperaturepf;

the reaction in the reaction vessels is 1o 'tained at that commonly employedwitlrthe particular catalyst, usually such temratures are between 2009 and 540 C.-an particularly betw'een;300 and 450 C. Be-' I tweeneach pair ofreaction vessels the reaction gases are treated to remove methanol as far as possible for instance by 000 and/or scrubbing with water, after .whi' treatment the gases. may, if, nry, be again raised to the reaction temperature by any suitable means before passing on to the next reaction vessel of the series. If desired a sufliciently large'number of vesse may be employed in the series to ensure that substantially all the gas undergoes conversion; four or five reaction vessels are usually suitable for this purpose.

' The accompanying diagrammatic drawing serves to illustrate such form of execution of the invention.

Referring to the'drawing, 1 is a compressor which supplies the water gas under the requisite pressure (e. g. -150" atmospheres). 2, 2a, 2b, 2c, 2d and 2e are the reaction vessels, the reaction vessels 2 and 2a vbeing provided respectively with a catalyst composed of pure zinc oxide and a catalyst composed of zinc oxide and chromium oxide. The reaction vessels 26, 20,212 and 2e are each charged with a catalyst composed 'of copper provided with a receiver oxideand zinc oxide, which catalyst is sen-. sitive to sulphur poisoning. The reaction vessels are connected as an open chain in series in the manner shown. Between each pair of reaction vessels a condenser (3, 3a, 3b, 3c and 3d) is rovided to separate the methanol produce each condenser being 4a, 4b, 4c and 4d)'.. Between the final reaction vessel 26 and the exhaust 5 a condenser 3e is provided to separate methanol produced in the reaction vessel 20, the condenser 36 being provided with a receiver 4e. Each of the reaction vessels is provided with an electric heater 6, 6a, 6b, 60, 6d and 66, these heaters enabling the reaction temperature in the vessels 2, 2a, 2b etc. to be attained or controlled. Be.- tween the reaction vessels .2 and 2a there is provided a heat exchanger. 7 which-heats the gases passing from the condenser 3 to the vessel 2a by means of the hot reaction gases leaving the reaction vessel 2. Similar heat exchangers 7a, 7 b, 70 and 7d are arranged between each of the other airs of reaction vessels. Between the reaction vessel 2e and condenser 3e, is provided a similar heat exchanger 7e which heats the gases passing from the compressor 1 to the reaction vessel 2 by means of the hot gases passing from the reaction vessel 2e to the condenser 36.

Assuming that the. apparatus is being started up. The water gas passes under the desired pressure (say 100-150 atmospheres) from the compressor 1 via the pipe 8 to the heat exchanger 76 and from thence via the pipe 9 to the reaction vessel 2 (i. e. the first reaction vessel in the series). On entering this reaction vessel 2 the. gases are raised to a temperature to initiate the reaction (e. g. 25 0350 C.) by means of the electric heater 6. After'passing from the heater 6 the gases pass through the zinc oxide catalyst and leave the reaction vessel 2 by the pipe 10. In their passage through the catalyst the gases, of course, get hotter through the exothermic reaction to methanol and they leave the vessel 2 at a considerable higher temperature (e. g. 350-400 G.) than that obtaining in the region of the heater 6. From the pipe 10 the heated reaction gases pass via a heat exchanger 7 to the condenser 3 wherein the methanol produced in the reaction vessel 2 is condensed and passes to'the receiver 4. From the condenser .3 the uncondensed gases pass via the pipe 11 to the heat exchanger 7 wherein they are heated by heat exchange with the heated gases passing from the pipe '10 to the con-- From the heat exchanger 7 the v denser 3. gases so'heated pass by the pipe 12 to the reaction vessel 2a (the second reaction vesselin the series). ,Such heat as may be necessary. to bring the ses again to the reaction ternperature formitiating the reaction to methanol is supplied. b the electriefheater 6a. The gases pass on om the vessel 2a, via the catalyst comprising copper oxi heat exchanger 7a, condenser 31 and heat ex- I changer 7a to the next reaction vessel (reaction vessel 26) in the series in manner similar to that in which they pass from the vessel 2 to 2a. After leaving the condenser '30! substantially no sulphur compounds remain 7 in the. gases, thereby avoiding difliculty of poisoning the sensitive catalyst (copper, zinc and zinc oxide) contained in the remaining reaction vessels of the series. The gases pass from the reaction vessel 26 successively to and through the vessels 2c, 2d and 2c in 'a manner similar to their passage through the v vessels 2a and 2b. After leaving the vessel 28 they pass via the heat exchanger 7e to the condenser 36 and exhaust 5. By passing through the heat exchanger 7 e the hot gases leaving the reaction vessel 26 heat up the gases passing via'the pipes 8 and 9to the vessel 2, the first reaction vessel of the series, thereby enabling the heater 6 to be used simply as a booster heater or for control purposes once the apparatus is in full operation.

- What I claim and desire to secure'by Lettcrs Patent is manufacture of methanol by subjecting a mixture of carbon 1. Process for the monoxide and hydrogen to elevated temperatures and pressure in presence of catalysts,

which comprises passing the reaction gases under the requisite temperature andpressure successively over at least one catalyst mass selected from the oup consisting of zinc oxide andzino oxide p us chromium oxide, and thereafter over at least! one methanol catalyst sensitive to sulphurfpoisoning.

2. Process for the manufacture of methanol by subjecting a mixtureof carbon monoxide and hydrogen to elevated temperaturesand pressure in presence of catalysts,

which comprises passing the reaction gases under the requisite temperature and pressure successively over atleas .one ca talyst mass selected from the group conslstlng of z nc oxide and zinc oxide plus chromium oxide,

and thereafter over at least one methanol 3. Process for. the manufacture .of methanol by subjecting 'a mixture of carbon monoxide and hydrogen to elevated temperatures and pressure in presence of catalysts, which comprises passing the reaction gases under the requisite temperature and pressure successively over at least one catalyst mass composed of mm: oxide andchromium oxide, and thereafter ovevat least one catalyst mass composed of zinc oxide and copper oxide.

4. Process for the manufacture methanol by subjecting a mixture of carbon monoxide and hydrogen to elevated temperatures and-pressure, and wherein the. reaction gases are-caused to pass under the requisite temperature and pressure successively through a series of reaction'vessels charged with catalyst masses and arranged as an open chain, characterized in that the gases are caused to pass through at least one reaction vessel charged with a catalyst mass selected from the group consisting of zinc oxide and zinc oxide plus chromium oxide, and thereafter through at least one reaction vessel charged with a methanol catalyst sensitive to sulphur poisoning. f

. 5. Process for the manufacture" methanol by subjecting a mixture of carbon monoxide and hydrogen to elevated temperatures and pressure, and wherein the reaction gases are caused to pass under therequisite temperature and pressure successively through a series of reaction vessels charged with catalyst masses and arranged as an open chain, characterized in that the gases are caused to pass through at least one reaction vessel charged with a catalyst mass selected from the group consisting of zinc oxide and zinc oxide plus chromium oxide, and thereafter through at least one reaction vessel charged with a methanol catalyst comprising copper oxide.

6. Process for the manufacture methanol by subjecting a mixture of carbon monoxide and hydrogen to elevated temperatures and pressure, and wherein the reaction gases are caused to pass under the requisite temperature and pressure through a series of reaction vessels charged with catalyst masses and arranged as an open chain, characterized in that the gases are caused to pass through at least one reaction vessel charged with a catalyst mass com posed of zinc oxide and chromium oxide, and thereafter through at least one'react-ion vessel charged with a catalyst mass composed of zinc oxide and copper oxide.

7. In a process according to claim 4 the step of condensing the methanol from the reaction gases in their passage between the catal st masses of the series.

8. rocess according to claim 6 and wherein the reaction gases are passed through a number of reaction vessels, which number is sufficiently large to ensure that substantiall all the gases underl'go conversion to methano In testimony w ereof, I have hereunto subscribed my name.

HENRY DREYFUS.

successively 

